Western River Crab (Potamonautes perlatus)

Its main habitat is rivers, but it does also occur widely in farm dams, where it often is regarded as a pest with a propensity for digging tunnels in earth dams.

Ecologically the species often is quite important, as it is a detritus shredder, a predator of small fish and amphibians, and a major prey item for large fish, otters, aquatic reptiles, and various other animals.